Tuesday, March 02, 2010

Impending large-scale unemployment results in fewer males being born

Here’s a rather unexpected result of mass layoffs and high unemployment: the stress causes pregnant women to spontaneously abort more males, thus contributing to future gender gap.

To our ancient ancestors, those signs would presumably be signals of impending drought or other natural disaster, which would indicate a coming food scarcity. [Ralph] Catalano and colleagues concluded the closest thing we have today is the announcement of mass layoffs at major employers, which impacts “the degree to which the larger population perceives a threat to its economic security.”

Such threats are bad news to small male fetuses because “a relatively large fraction” of them fall near “a critical rank below which gestations spontaneously end,” the researchers explain. If they are born, these small males are more likely to die than larger infants and females of equivalent size.

The researchers examined California’s ratio of male to female births from mid-1995 to the end of 2007 and compared it to the federal Labor Department’s monthly statistics on mass layoffs in the state. The government reports a mass layoff has taken place when 50 or more people file for unemployment insurance from a single company over five weeks.

After doing some complex calculations, they estimated that news of impending mass layoffs “predicted the loss of 3,090 males in utero” during the 61 months (out of the 141 they examined) in which unemployment claims exceeded the expected number.